Low-travel key mechanisms using butterfly hinges

ABSTRACT

A key mechanism can include one or more butterfly hinges. Each butterfly hinge includes a double wing design operative to move between a depressed position and non-depressed position. Hinged coupling mechanisms couple respective arms of the wings together.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. ProvisionalPatent Application No. 61/720,373, filed Oct. 30, 2012 and titled“Low-Travel Key Mechanisms Using Butterfly Hinges,” the disclosure ofwhich is hereby incorporated herein in its entirety.

TECHNICAL FIELD

The disclosed embodiments relate generally to electronic devices, andmore particularly to input devices for electronic devices.

BACKGROUND

Many electronic devices typically include one or more input devices suchas keyboards, touchpads, mice, or touchscreens to enable a user tointeract with the device. These devices can be integrated into anelectronic device or can stand alone as discrete devices that cantransmit signals to another device either via wired or wirelessconnection. For example, a keyboard can be integrated into the housingof a laptop computer or it can exist in its own housing.

It is often desirable to reduce the size of electronic devices andminimize machining costs and manufacturing time of such devices. Forexample, laptops may be designed to be as small and light as possible,but input devices such as a keyboard may occupy relatively largeportions of the available interior space. One way to alleviate designconstrains of a keyboard is to minimize the z-stackup of key mechanisms.Accordingly, what is needed is an improved key mechanism design.

SUMMARY

In one aspect, a key mechanism includes a butterfly hinge. The butterflyhinged key mechanism according to various embodiments enablesubstantially low travel distances with desired tactile response. Thekey mechanism uses a double wing design operative to move between adepressed position and non-depressed position. In one embodiment, a keymechanism includes a keycap assembly, a support structure, and abutterfly hinge having two independently articulating wings, each wingcoupled to the keycap assembly and the support structure, wherein eachwing is operative to pivot about its own pivot axis during a keystrokeof the key mechanism.

In another aspect, a key mechanism includes a keycap assembly, a supportstructure, and a butterfly hinge that includes two separate wingspositioned adjacent to each other such that a cavity is formed betweenthe two wings. Each wing can include a pair of pivot pins and a pair ofkeycap assembly pins, where the pivot pins are coupled to the supportstructure and the keycap assembly pins are coupled to the keycapassembly. In addition, a switch, such as a dome switch, can be securedwithin the cavity between the keycap assembly and the support structure.The switch is operative to bias the keycap assembly in a first position.For example, the switch can bias the keycap assembly upwards when thekey mechanism is not subjected to a keystroke event.

In another aspect, a key mechanism includes a keycap assembly and acarrier structure that includes a plate and arms fixed to opposite endsof the plate. Each arm can include pivot pin retaining members. Abutterfly hinge includes two separate wings positioned adjacent to eachother, each wing comprising a pair of pivot pins and a pair of keycapassembly pins. The pivot pins are coupled to the carrier structure andthe keycap assembly pins are coupled to the keycap assembly. The carrierstructure can house an electronics package that includes circuitry suchas a switch, light source, or a display.

In another aspect, a butterfly assembly can include first and secondwings, each wing comprising a pair of pivot pins and a pair of keycapassembly pins. The pins of each pair are coaxially aligned with theirown respective pair axis. First and second hinges couple the first andsecond wings together. A cavity is formed between the first and secondwings when the wings are hinged together.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and advantages of the invention will becomemore apparent upon consideration of the following detailed description,taken in conjunction with accompanying drawings, in which like referencecharacters refer to like parts throughout, and in which:

FIG. 1 shows a perspective view of a computing device having a keyboardincorporated therein in accordance with an embodiment;

FIG. 2 shows an illustrative perspective view of a section of a keyboardin accordance with an embodiment;

FIG. 3 shows a generic and illustrative exploded view of a key mechanismin accordance with an embodiment;

FIGS. 4A-4B show respective illustrative partial cross-sectional viewsof a key mechanism in a non-depressed position and depressed position inaccordance with an embodiment;

FIGS. 5A-5C show illustrative views of butterfly hinge in accordancewith an embodiment;

FIG. 6 shows illustrative top view of a key mechanism in accordance withan embodiment;

FIG. 7 shows an illustrative exploded view of the key mechanism of FIG.6 in accordance with an embodiment;

FIG. 8 shows an illustrative perspective view of a keycap assembly inaccordance with an embodiment;

FIG. 9 shows an illustrative perspective view of an electronics packagein accordance with an embodiment;

FIG. 10 shows an illustrative perspective view of keycap assembly andelectronics package in accordance with an embodiment;

FIG. 11 shows an illustrative top view of a butterfly hinge inaccordance with an embodiment;

FIG. 12 shows an illustrative top view of a support structure inaccordance with an embodiment;

FIG. 13 shows an illustrative top view of a butterfly hinge coupled tosupport structure in accordance with an embodiment;

FIG. 14A shows an illustrative top view of an alternative supportstructure in accordance with an embodiment;

FIG. 14B shows an illustrative top view of a yet another alternativesupport structure in accordance with an embodiment;

FIGS. 15-16 show illustrative cross-sectional views of a key mechanismin accordance with an embodiment;

FIG. 17 shows an illustrative perspective view of another key mechanismin accordance with an embodiment;

FIG. 18 shows an illustrative cross-sectional view of the key mechanismof FIG. 17 in accordance with an embodiment;

FIG. 19 shows an illustrative perspective view of a butterfly hinge andsupport structure in accordance with an embodiment;

FIG. 20 shows an illustrative exploded view of a key mechanism inaccordance with an embodiment;

FIG. 21 shows an illustrative top view of a butterfly hinge inaccordance with an embodiment;

FIG. 22 shows an illustrative top view of a butterfly hinge coupled to acarrier structure in accordance with an embodiment;

FIG. 23 shows an illustrative bottom view of a butterfly hinge coupledto a carrier structure in accordance with an embodiment;

FIG. 24 shows an illustrative perspective view of a key mechanism inaccordance with an embodiment;

FIG. 25 shows an illustrative cross-sectional view of key mechanism inaccordance to an embodiment;

FIG. 26 shows an illustrative perspective view of a key mechanism inaccordance with an embodiment;

FIG. 27 shows an illustrative cross-sectional view of key mechanism inaccordance to an embodiment;

FIG. 28 shows an illustrative perspective view of carrier structurecoupled to a support structure in accordance with an embodiment;

FIGS. 29A-29B show illustrative views of a butterfly hinge in accordancewith an embodiment;

FIGS. 30A-30C show illustrative views of a butterfly hinge in accordancewith an embodiment;

FIGS. 31A-31C show illustrative views of a butterfly hinge in accordancewith an embodiment;

FIGS. 32A-32C show illustrative views of a butterfly hinge in accordancewith an embodiment; and

FIGS. 33A-33B show illustrative views of a butterfly hinge in accordancewith an embodiment.

DETAILED DESCRIPTION

Some embodiments described herein provide a key mechanism for an inputdevice such as a keyboard that includes a butterfly hinge. The butterflyhinged key mechanism can enable substantially low travel distances withdesired tactile response. For example, a butterfly hinged key mechanismcan enable keystrokes ranging between 0.1 mm to 2.0 mm, and in someembodiments, the keystroke can be 0.5 mm or 0.75 mm. The key mechanismuses a double wing design operative to move between a depressed positionand non-depressed position. Corresponding arms of the butterfly hingeare coupled together with coupling mechanisms. The coupling mechanismscan be, for example, a flexible or living hinge or a gear hinge. Thewings of the butterfly hinge articulate independently with each wingoperative to pivot about its own pivot axis during a keystroke of thekey mechanism.

FIG. 1 shows a perspective view of a computing device 10 having akeyboard 12 incorporated therein. Computing device 10 can be anysuitable computing device, such as, for example, a laptop computer, adesktop computer, a telephone, smart phone, or gaming device. Keyboard12 can be integrally formed within computing device 10. In otherembodiments, a keyboard according to an embodiment can be separate fromthe computing device and can stand alone as a self-contained device. Forexample, a keyboard may be a communication interface such as, forexample, a wired keyboard or a wireless keyboard that can transmit datato and from a computing device.

FIG. 2 shows an illustrative perspective view of a section of keyboard12 (shown as element 12) including a key 14. FIG. 2 also shows a stackupof web 30 and support structure 70. Web 30 can be a skeletal structurethat surrounds each key of keyboard 10 and provides structural andcosmetic attributes to keyboard 10. Web 30 can be secured to supportstructure 70 using any suitable approach such as, for example, byadhesive, glue, weld, pins, interface fits, or any combination thereof.Support structure 70 can provide the platform for components containedwithin a keyboard. Support structure 70 is sometimes referred to as afeature plate. As defined herein, support structure 70 can include anycombination of a feature plate, circuit board, and retaining mechanismsfor use in various keyboard mechanism embodiments.

Key mechanisms according to various embodiments discussed herein providea substantially low travel keystroke while maintaining a desired tactilefeel over the lifetime of the keyboard. Decreasing the keystrokedistance enables keyboard 10 to be built thinner than contemporarykeyboards. For example, key mechanisms according to various embodimentsdescribed herein can enable keystrokes ranging between 0.1 mm to 2.0 mm,and in some particular embodiments, the keystroke can be 0.5 mm or 0.75mm.

The tactile performance of the key mechanism is consistent regardless ofwhere a user presses down on key 14. That is, the tactile response ofkey 14 is substantially the same if the user pressed down at the center(at region 15 a), the corner (at region 15 b), or the edge (at region 15c) of key 14. In addition to having a uniform tactile response, themovement of key 14 during a keystroke is also uniform regardless ofwhere it is depressed. For example, imagine a reference plane exists atthe top surface of key 14. When key 14 is pressed at region 15 a, itsmovement is one in which the top planar surface of key 14 remainsparallel to the reference plane throughout the keystroke. The same istrue when key 14 is depressed at a corner or edge; the top planarsurface remains parallel or substantially parallel to the referenceplane throughout the keystroke. Maintaining this parallel movement, witha relatively low travel, and desired tactile response, is accomplishedusing a butterfly hinge mechanism according to various embodiments.

Referring now to FIG. 3, a generic and illustrative exploded view of keymechanism 12 is shown. Reference will also be made to FIGS. 4-5 toassist in the description of how key mechanism 12 operates. Keymechanism 12 can include keycap 14, substructure 20, web 30, switch 40,butterfly hinge 50, and support structure 70. Assembly of key mechanismis as follows. Keycap 14 is secured to substructure 20 to form a keycapassembly. The keycap assembly can fit within the inner perimeter of web30, and web 30 is secured to an outer boundary of support structure 70.In other embodiments, the keycap assembly can exist above web 30.Butterfly hinge 50 is secured to substructure 20 and support structure70, and is also contained within the inner perimeter of web 30. Switch40 resides within cavity 53 of butterfly hinge 50 and can be secured toeither the keycap assembly or support structure 70.

Keycap 14 is the portion of key mechanism that a user depresses during akeystroke. Keycap 14 can take any suitable shape and can be constructedfrom any suitable material. For example, keycap 14 can be constructedfrom plastic, glass, or metal. In some embodiments, keycap 14 can beconstructed from a translucent material so that a backlight can shinethrough. Moreover, a translucent keycap can be masked so that itdisplays a character.

Substructure 20 can take any suitable shape and be constructed from anysuitable material. Substructure 20 can fulfill several differentfunctions in its use in key mechanism. In one function, it provides pinretaining mechanisms 22 for coupling to butterfly hinge 50. Inparticular, substructure can include four pin retaining mechanisms 22,each one operative to couple to one of keycap assembly pins 54 and 57 ofbutterfly hinge 50. Additional details of pin retaining mechanisms 22are discussed in more detail below.

As another function, substructure 20 can serve as a light guide panel(hereinafter “LGP”) for distributing backlight emitted from a lightsource such as, for example, a LED. In embodiments that use substructure20 as a LGP, the shape of substructure 20 can be designed to minimizethe impact of backlighting performance. For example, substructure 20 canoccupy an outer periphery of keycap 14, thereby leaving an interiorportion of keycap largely unobfuscated. The use of a LGP as part ofsubstructure 20 is discussed in more detail below.

The combination of keycap 14 and substructure 20 (and potentially othercomponents such as switch 40, electronics (not shown), and flexcircuitry (not shown)) is sometimes referred to herein as a keycapassembly. In some embodiments, depending on the stiffness of keycap 14,a relatively strong substructure is needed to provide the rigidityneeded for property operation of key mechanism 12. For example, ifkeycap 14 is constructed from a plastic, substructure 20 may beconstructed from metal. In other embodiments, keycap 14 can beconstructed from a relatively stiff material such as glass andsubstructure can be constructed from a plastic or metal material. In yetanother embodiment, keycap 14 and substructure 20 can be an integrallyformed keycap assembly. For example, keycap 14 and substructure 20 canbe formed from a single plastic mold or a single piece of machinedglass.

Switch 40 can be any suitable mechanical switch such as a dome switch. Ametal dome switch or an elastomeric dome switch may be used, forexample. As will be explained more detail in connection with FIG. 4,switch 40 can bias the keycap assembly to be in its natural,non-depressed position. In other words, when key mechanism is notundergoing a keystroke event, switch 40 can bias the keycap assembly tobe in its non-depressed position. When key mechanism 12 is subjected toa keystroke event, switch 40 can buckle under the force applied tokeycap 14, thereby enabling the keycap assembly to be in its depressedposition. When the keycap assembly is in its depressed position, thekeystroke can be registered by circuitry associated with switch 40 or byother circuitry contained within key mechanism (e.g., a parallel platesensor membrane).

Butterfly hinge 50 functions as the movable hinge that enables thekeycap assembly to move relative to support structure 70. Butterflyhinge 50 can include wings 51 and 52, which are separate componentscoupled together by coupling mechanisms 60. Wing 51 includes keycapassembly pins 54 and pivot pins 55, and wing 52 includes keycap assemblypins 57 and pivot pins 56. Wings 51 and 52 may each include a cutoutsuch that when wings 51 and 52 are coupled together, cavity 53 exists.Cavity 53 can have any suitable shape such as, for example, a square, arectangle, circle, or ellipse.

Keycap assembly pins 54 and 57 are coupled to pin retaining mechanisms22 a, 22 b of substructure 20. Pivot pins 55 and 56 are coupled to pivotpin retaining members 75 and 76, respectively, of support structure 70.The manner in which pins are coupled to substructure 20 and supportstructure 70 vary depending on specific embodiments, discussed below.

Coupling mechanisms 60, though coupling wings 51 and 52 together, mayenable wings 51 and 52 to move independent of each other. Thus, if onewing were locked in a position, the other wing would be free to move,and vice versa. However, as will be explained in FIGS. 4-5, wings 51 and52 are both secured to support structure 70 and are operative to move(or flap) in concert with each other, with coupling mechanism 60changing between substantially flat-shaped and v-shaped positions. Manydifferent embodiments of coupling mechanisms 60 can be used withbutterfly hinge 50. These embodiments are discussed in more detail inconnection with the description below accompanying FIGS. 4-5. In otherembodiments, coupling hinges 60 can be omitted from butterfly hinge 50.

Support structure 70 can be constructed from any suitable material orcombination of different materials. The specific construction andmaterials used depends on particular key mechanism embodiment beingemployed, and thus these notable features are discussed in more detailbelow. One notable feature of structure 70 shown in FIG. 3 is cutouts77. Cutouts 77 are positioned in predetermined positions on structure 70so that pin retaining mechanism 22 of substructure 20 can fit into arespective cutout when the key mechanism is in its depressed position.This nestling of components within each other during a keystroke helpskey mechanism 12 maintain its relatively thin z-height.

Referring now to FIGS. 4A-4B, illustrative partial cross-sectional viewsof key mechanism 12 are shown in a non-depressed position (FIG. 4A) anddepressed position (FIG. 4B). Both figures show keycap 14, pin retainingmechanism 22 a, 22 b of substructure 20, wing 51 with pivot pin 55 andkeycap assembly pin 54, wing 52 with pivot pin 56 and keycap assemblypin 57, coupling member 60, switch 40, support structure 70, and pivotpin retaining members 75 and 76. Other components of key mechanism 12have been omitted to provide less cluttered figures and to promote easeof discussion.

FIGS. 4A-4B also show keycap plane 400, pivot pin plane 410, andstructure plane 420. Regardless of whether key mechanism 12 is in itsdepressed or non-depressed state, the position of pivot pin plane 410and structure plane 420 remain fixed, as indicated by the set of doublearrows demarcating the z-height (shown as Zfixed) between the two planesin both figures. The z-height between keycap plane 400 and the structureplane 420, however, changes depending on the position of key mechanism12. In the depressed position, the z-height is Zdepressed, as shown, andin the non-depressed position, the z-height is Znon-depressed.

Pivot pin retaining members 75 and 76 are operative to securely holdpivot pins 55 and 56 in place, while enabling pivot pins 55 and 56 torotate within pivot pin retaining members 75 and 76. Keycap assembly pin57 is coupled to pin retaining mechanism 22 a, which can secure keycapassembly pin 57 to substructure 20 (not shown) in a manner similar tohow pivot pin retaining members 75 and 76 secure their pins. Thus, pinretaining mechanism 22 a may rotate when keycap 14 is undergoing akeystroke. Keycap assembly pin 54 can be coupled to pin retainingmechanism 22 b, which is operative to enable keycap assembly pin 54 toslide horizontally within the pin retaining mechanism as key mechanism12 travels up and down. Thus, the pin retaining system uses three setsof pin retaining mechanisms (one set for each pair of pins 57, 56, and55) for securing rotating pins 57, 56, and 55 in place with minimalhorizontal movement, and a fourth set (for pins 54) for securing slidingpins 54 in place with a fixed amount of horizontal movement. Additionalaspects and features on the retaining mechanisms are discussed in moredetail below for various different embodiments.

Referring collectively now to FIGS. 4A-4B and FIGS. 5A-5C, wings 51 andwings 52 pivot about their own respective pivot axes. Wing 51 pivotsabout axis 510, which runs co-axially with the center axis of pivot pins55, and wing 52 pivots about axis 520, which runs co-axially with thecenter axis of pivot pins 56. Since pivot pins 55 and 56 are secured inposition with respect to structure 70 (as shown by fixed z-heightZfixed), it is the outer portions of wings 51 and 52 (particularly atkeycap assembly pins 54 and 57) that move relative to pivot pins 55 and56.

In the non-depressed position, switch 40 is in its natural unbuckledposition. In this position, switch 40 biases keycap 14 upwards when keymechanism 12 is not being subjected to a keystroke event. With theupward bias of switch 40, it pushes keycap 14 up, resulting in havingpin retaining mechanism 22 a, 22 b pull keycap assembly pins 54, 57 ofwings 51, 52 up. Since, pivot pins 55 and 56 are secured in place, wings51 and 52 pivot about their own respective pivot axes 510 and 520, andkeycap assembly pin 57 remains fixed in position, keycap assembly pin 54slides horizontally to the left (shown here as the −X direction) withinpin retaining mechanism 22 b. As shown, in the non-depressed position,wings 51 and 52 resemble a v-shaped hinge, with its outer portions(e.g., pin regions 57 and 54) raised relative to pin plane 410.

In the depressed position, switch 40 is buckled, and keycap 14 has moveddown vertically, thereby pushing the outer portions of wings 51 and 52down towards support structure 70. Pins 57, 56, and 55 are secured inplace and rotate within their secured positions, whereas keycap assemblypin 54 slides horizontally within its retaining mechanism in the +Xdirection. As shown in FIGS. 4A-4B, the relative position of keycapassembly pin 54 moves to the +X direction when the key mechanism 12 isin the depressed position. Moreover, in the depressed position, wings 51and 52 resemble a log shaped hinge, with all pins 54-57 in substantiallythe same plane.

Use of the butterfly hinge 50 in key mechanism 12 provides not only alow travel keystroke, but a stable key mechanism. The double wing designof butterfly hinge 50 distributes loading evenly with respect to thekeycap assembly. The evenly distributed loading is accomplished byplacing the load bearing keycap assembly pins 57 and 54 at the outerportions of wings 51 and 52, respectively. This stable loading istranslated to keycap 14 because regardless of where a user presses downon keycap 14, the load will be distributed across the key, resulting ina tactically desirable and non-wavering keystroke.

Referring now to FIGS. 6-16, a low travel key mechanism according to anembodiment is discussed. Features discussed above in connection withFIGS. 2-5 apply to similar features discussed in connection with FIGS.6-16, however, notable features will be discussed in more detail. FIG. 6shows an illustrative top view of key mechanism 612, showing keycap 614and a few internal features shown by hidden lines. In particular,substructure 620 (with integrated light guide panel) and LED 648 areshown by hidden lines.

FIG. 7 shows an illustrative exploded view of key mechanism 612. Asshown, key mechanism 612 can include keycap 614, substructure 620, web630, electronic package 642, butterfly hinge 650, support structure 670,and cover plate 680. Cover plate 680 can be a printed circuit board or aheat spreader. FIG. 8 shows an illustrative perspective view of thebottom of keycap 614 and substructure 620, with substructure 620 securedto keycap 614. In this embodiment, substructure 620 doubles as a pinretaining structure and a LGP. The LGP aspect of substructure 620 isevident in that it occupies a majority of the surface area of keycap 614and includes notch 624 for enabling a light source, such as LED 648, tofit adjacent to the LGP.

As shown, substructure 620 has pin retaining mechanisms 622 a and 622 blocated near the corners of keycap 614. Pin retaining mechanisms 622 aare operative to securely couple pins and allow the pins to rotatefreely within. In particular, pin retaining mechanisms 622 a can bec-clip retaining members. Pin retaining mechanisms 622 b are operativeto slidably couple pins therein. That is, the pins are retained withinthe mechanism, but are allowed to slide horizontally within themechanism when the key mechanism is undergoing a keystroke event. Pinretaining mechanism 622 b can have an extruded L-shape that extends aminimum distance sufficient to contain the sliding pin. Note that bothpin retaining mechanisms 622 b may face each other. It is understoodthat any suitable number of different configurations of pin retainingmechanisms 622 b can be used to achieve the desired coupling effect.

FIG. 9 shows an illustrative perspective bottom view of electronicspackage 642. Electronics package can include switch 640, which ismounted to flexible printed circuit board (PCB) 643, connector portion644, support portion 645, and LED 648. In other embodiments, electronicspackage 642 can include a display such as OLED display. Referring toboth FIGS. 9 and 10, electronics package 642 is mounted to substructure620. In this arrangement, the base of switch 640 is pressed againstsubstructure 620, and LED 648 fits within notch 624 (FIG. 8). Supportportion 645 floats relative to PCB 643 via connector portion 644 andsurrounds keycap 614 and substructure 620. Thus, when key mechanism 612is assembled, the nipple side of switch 640 faces downward towardssupport structure 670 (not shown), and passes through cavity 653 ofbutterfly hinge 650 (shown in FIG. 11). In addition, when assembled,support portion 645 can align with web 630 (FIG. 7) and both web 630 andsupport portion 645 can be secured to support structure 670 (FIG. 7).

FIG. 11 shows an illustrative top view of butterfly hinge 650. Butterflyhinge 650 includes wings 651 and 652. No coupling mechanisms are showncoupling wings 651 and 652 together in this detailed view. Wing 651 caninclude pivot pins 656, keycap assembly pins 657, and upstop members658. Wing 652 can include pivot pins 655, keycap assembly pins 654, andupstop members 659. Both wings 651 and 652 are shaped so that cavity 653exists when the wings are placed adjacent to one another. Pivot pins 655and 656 and upstop members 658 and 659 extend away from the outsidesurface of butterfly hinge 650, whereas keycap assembly pins 654 and 657extend within butterfly hinge 650. Pivot pins 655 and upstop members 659may be coplanar with each other and extend about the same distance awayfrom butterfly hinge 650. Similarly, pivot pins 656 and upstop members658 may be coplanar with each other and extend about the same distanceaway from butterfly hinge 650.

FIG. 12 shows an illustrative top view of support structure 670. Supportstructure 670 has pivot pin retaining members 675 and 676, and upstops678 and 679. Pivot pin retaining members 675 and 676 are operative tosecure pivot pins 655 and 656, respectively, in place but enable thepins to rotate freely within. Pivot pin retaining members 675 and 676may be c-clip types of retaining members. Upstops 678 and 679 may behook shaped members operative to engage upstop members 658 and 659,respectively. Upstops 678 and 679 ensure that wings 651 and 652 do nottravel up beyond a pre-determined vertical distance when key mechanismis in its natural, un-depressed position. Support structure 670 can alsoinclude cutouts 677.

FIG. 13 shows an illustrative top view of butterfly hinge 650 coupled tosupport structure 670. In this view, pivot pins 655 and 656 are securedto support structure 670 via pivot pin retaining members 675 and 676,respectively, and upstop members 658 and 659 are positioned underupstops 678 and 679, respectively. FIG. 13 also shows how end portions(centered around keycap assembly pins 654 and 657) are positioned overcutouts 677. FIG. 15 shows an illustrative cross-sectional view of keymechanism 612, showing the interaction of pivot pins 655 and 656 withpivot pin retaining members 675 and 676 and, upstop members 658 and 659with upstops 678 and 679.

FIGS. 14A-14B show perspective views of alternative support structuresaccording to various embodiments. In particular, FIG. 14A shows adifferent retaining member configuration for securing butterfly hinge650 to support structure 1400. Support structure 1400 includes c-clipretaining members 1422, and hook retaining members 1432 for retainingpins of a butterfly hinge (not shown). Structure 1400 also includesupstop members 1440.

FIG. 14B shows support structure 1450 that includes pivot pin retainingmember 1462 and upstop members 1470. Pivot pin retaining member 1462 isa one piece construction including two circular eyes for holding pivotpins. Pivot pin retaining member 1462 can have a spring loaded bias topress against the butterfly hinge when its pivot pins are secured withinthe eyes.

FIG. 16 shows another illustrative cross-sectional view of key mechanism612 in a non-depressed position. This view shows switch 640 in anon-buckled position, wings 651 and 652 in a v-shaped arrangement, pinretaining mechanisms 622 a, 622 b, keycap assembly pins 657 and 654, andother components.

FIGS. 17-19 show various illustrative views of another key mechanismaccording to an embodiment. In particular, FIG. 17 shows an illustrativeperspective view of key mechanism 1712 in a non-depressed position. FIG.18 shows a cross-sectional view taken along line 18-18 in FIG. 17. AndFIG. 19 shows an illustrative perspective view of key mechanism withouta keycap assembly. Key mechanism 1712 exhibits many of the sameattributes of the generic key mechanism of FIGS. 2-5, but includes moredetails regarding its hinge and support structure. As shown in FIG. 17,key mechanism 1712 can include keycap 1714, laminate layer 1716,substructure 1720, switch 1740, butterfly hinge 1750, and supportstructure 1770.

Butterfly hinge 1750 can include wings 1751 and 1752. Wing 1751 caninclude pivot pins 1755 and keycap assembly pins 1754. Wing 1752 caninclude pivot pins 1756 and keycap assembly pins 1757. Keycap assemblypins 1754 and 1757 are coupled to substructure 1720, and pivot pins 1755and 1756 are coupled to support structure 1770. Pivot pins 1755 and 1756are secured within slots 1775 and 1776 of support structure 1770. Slots1775 and 1776 may be cavities in the structure 1770 that are covered bylaminate material 1716. In some embodiments, laminate material 1716 canbe the same as a web (such as web 30). In effect, laminate material 1716locks pivot pins 1755 and 1756 in place within support structure 1770.In this embodiment, pivot pins 1755, 1756 and keycap assembly pins 1754,1757 all extend away from butterfly hinge 1750.

Switch 1740 can fit in a cavity existing between wings 1751 and 1752, asshown. In this particular embodiment, the base of switch 1740 can resideon support structure 1770, as opposed to being fixed to substructure1720. When key mechanism 1712 is in its non-depressed position, switch1740 is in its unbuckled state and props or biases the keycap assemblyup. When key mechanism 1712 is in its depressed position, switch 1740will be buckled and wings 1751 and 1752 will be pressed down in a logshaped position, with all pins 1754, 1755, 1756, 1757 in substantiallythe same plane.

Each wing can include upstops 1910, which are operative to limit theup-travel of the wings when the key mechanism is in its undepressedposition. Upstops 1910 may engage laminate layer 1716 in the undepressedposition. Upstops 1910 may be shaped at an angle to enable flushinterfacing with the laminate layer.

FIGS. 20-28 show various illustrations of a key mechanism 2012 using acarrier plate according to an embodiment. References to key mechanism2012 include all FIGS. 20-28, with occasional specific reference toindividual figures. The carrier plate, as opposed to the structuralsupport is responsible for securing the pivot pins of the butterflyhinge in place. In addition, the carrier plate can also support anelectronic package. Referring now to FIG. 20, there is shown an explodedview of key mechanism 2012. Key mechanism 2012 can include keycap 2014,substructure 2020, carrier plate 2090, electronics package 2042, switch2040, butterfly hinge 2050, web 2030, and circuit board 2080. Componentsdiscussed earlier in connection with FIGS. 2-5 may share characteristicswith similar components of key mechanism 2012. For example, keycap 2014and substructure 2020 and its interaction with keycap assembly pins ofbutterfly hinge 2050 is similar to how keycap 14 and substructure 20interact with butterfly hinge 50.

Carrier plate 2090 is constructed to fit within cavity 2053 (FIG. 21) ofbutterfly hinge 2050 and be secured to circuit board 2080. Carrier plate2090 can be secured to circuit board 2080 in any number of suitabledifferent ways. For example, it can be glued or welded to circuit board2080. As another example, carrier plate 2090 can have several posts thatextend from a bottom surface of the carrier plate and engage withcorresponding cavities in circuit board 2080. As yet another example,carrier plate 2090 can be secured in place with two or more clips 2802,as shown in FIG. 28. When carrier plate 2090 is secured to circuit board2080, it secures pivot pins 2056 and 2055 in place so that they are freeto rotate in place within pivot pin retaining members 2095 and 2096. Thepin arrangement of butterfly hinge 2050 is shown in more detail in FIG.21, and the pivot pin retaining members of carrier plate 2090 is shownin more detail in FIGS. 22, 23, 24, and 25.

Butterfly hinge 2050 can include two wings 2051, 2052 connected togetherusing a coupling mechanism (not shown). Any suitable coupling mechanismcan be used. Various examples of such coupling mechanism are describedin more detail below. Cavity 2053 can exist between the two wings 2051,2052 when placed adjacent to each other.

Carrier plate 2090 can be constructed from any suitable material such asmetal or plastic. The construction of carrier plate 2090 can include aflat plate 2091, which is flanked by two raised arm members 2092. Eachraised arm member 2092 can include pivot pin retaining member 2095 andpivot pin retaining member 2096. In addition, each raised arm member2092 can include two upstop protrusions 2099. Upstop protrusions 2099are operative to engage upstops 2059 of butterfly hinge 2050 when keymechanism 2012 is in its non-depressed position. Protrusions 2099prevent wings 2051, 2052 of butterfly hinge 2050 from traveling beyond afixed vertical up direction.

Flat plate 2091 can serve as a platform for electronics package 2042,which can include among other features, switch 2040, LED, light guidepanel, display, and/or flex circuitry. This arrangement promotes easyconnections between circuit board 2080 and electronics package 2042because carrier plate 2090 is directly connected to circuit board 2080.This is in contrast to the flex printed circuit board embodimentassociated with key mechanism 612 (described earlier). Moreover, asshown in this embodiment, switch 2040 is mounted such that its dome isfacing substructure 2020 and keycap 2014. Thus, when switch 2040 is inits unbuckled position, it is operative to bias keycap 2014 andsubstructure 2020 upwards.

Referring now to FIGS. 26 and 27, there are shown pin retainingmechanisms 2022 a, 2022 b of substructure 2020 interfacing with keycapassembly pins 2054 and 2057. In particular, FIG. 27 shows the differentpin retaining mechanisms, pin retaining mechanism 2022 a for securingkeycap assembly pin 2054 in place so that it rotates in place, and pinretaining mechanism 2022 b for enabling keycap assembly pin 2057 toslide horizontally when key mechanism 2012 is being depressed.

FIGS. 29-33 show several different butterfly hinge embodiments that canbe used in conjunction with a key mechanism. Each of the embodimentsdiscussed in connection with FIGS. 29-33 include two wings that arecoupled together with a coupling mechanism. The nature of the couplingmechanism varies and can include two general types: living hinge andgear hinge. A living hinge coupling mechanism can be a flexible materialor combination of materials that physically attaches the two wingstogether. A gear hinge is a coupling mechanism built into the wingsthemselves that allows for a gear-like interaction between the wings.

FIGS. 29A-29B show illustrative top and partial perspective views ofbutterfly hinge 2900 in accordance with an embodiment. Hinge 2900includes wings 2910 and 2920 coupled together with living hinge 2930.Wings 2910 and 2920 can include pins as shown and can be made, forexample, from a glass-filled plastic. Living hinge 2930 can be made froma plastic material that is softer than the material used to make thewings. Wings 2910 and 2920 also include self-locking structures 2912 and2922.

Butterfly hinge 2900 can be manufactured using a double-shot process,wherein the first shot creates wings 2910 and 2920, and the second shotforms living hinge 2930. When the second shot is applied, it self-locksitself to self-locking structures 2912 and 2922 to couple wings 2910 and2920 together. Note that the thickness of living hinge 2930 issubstantially thinner at center axis 2940 of butterfly hinge 2900 thanat other portions of living hinge 2930. The thinner section at thejunction between wings 2910 and 2920 can promote ease of flexing betweenwings 2910 and 2920.

FIGS. 30A-30B show illustrative top and perspective views of butterflyhinge 3000 in accordance with an embodiment. Butterfly hinge 3000 can bemanufactured by insert molding wings 3010 and 3020 around living hinge3030. Molded wings 3010 and 3020 can include the pins, as shown. Livinghinges 3030 can be part of a metal strip 3050 containing several livinghinges 3030 (as shown in FIG. 30C). Including several living hinges 3030on a single strip can increase manufacturing throughput of butterflyhinge 3000. After wings 3010 and 3020 are molded on to strip 3050, thestrip can be cut away to yield an individual butterfly hinge 3000 thatis suitable for use in a key mechanism. Wings 3010 and 3020 can beconstructed, for example, with a plastic such as a glass filled plastic.

Living hinge 3030 can be a relatively thin piece of metal (e.g., steel)that is operative to bend to enable wings 3010 and 3020 to move whenused in a key mechanism. Living hinge 3030 can include retentionfeatures 3012 and 3014 to promote adhesion to the wings when the wingsare molded thereto. When wings 3010 and 3020 are molded onto strip 3050,shutoffs can be used to prevent wings from completely covering livinghinge 3030, thereby leaving a portion of living hinge 3030 exposed.

FIGS. 31A-31C show various views of butterfly hinge 3100 in accordancewith an embodiment. Butterfly hinge 3100 can be constructed by couplingmetal wings 3110 and 3120 together with an injection molded living hinge3130. Wings 3110 and 3120 can be constructed from a die cast or forgedmetal. In one embodiment, wings can be formed from a zinc die cast. Inthis embodiment, the pins are also formed in the die cast or forgedmetal. Wings 3110 and 3120 can be constructed to have retention features3112 and 3122 to assist living hinge 3130 retention. Living hinge 3130can be any suitable compliant material capable of bending. For example,living hinge 3130 can be constructed from a plastic or rubber material.

FIGS. 32A-32C show illustrative views of butterfly hinge 3200 inaccordance with an embodiment. Butterfly hinge 3200 can be constructedfrom two metal cores 3201 and 3202 (shown by hidden lines) that areovermolded with a molding material. The molding material fullyencapsulates metal cores 3201 and 3202 to form wings 3210 and 3220,which each include pins formed by the overmold, and living hinge 3230.Cores 3201 and 3202 can be separate metal components with retentionfeatures 3205 incorporated therein. Retention features 3205 can enablethe injected molded material to self-lock itself to cores 3201 and 3202.

Living hinge 3230 can be formed from the overmold that couples cores3201 and 3202 together. It can be sized to be relatively narrow at thejunction between wings 3210 and 3220 to promote ease of movement. Hinge3200 can be constructed in batch fashion in that strip 3250 can containseveral cores. The cores can be overmolded and then die cut to yieldeach butterfly hinge 3200.

In another embodiment (not shown), a butterfly hinge can be constructedfrom two metal cores, having forged or die cast pins, that are at leastpartially overmolded with a molding material, but in a way so that thepins are left exposed. This way, the metal pins are exposed and formedfrom metal, as opposed to an injection molded plastic. A living hinge isformed from the injection molded plastic coupling the two corestogether.

FIGS. 33A-33B show illustrative views of butterfly hinge 3300 inaccordance with an embodiment. Hinge 3300 includes wings 3310 and 3320that each include pins and upstops, as shown. Wing 3310 has gear members3315 and wing 3320 has gear members 3325. Gear members 3315, 3325interface with each other to form a gear hinge.

Referring to FIG. 33B, a close up of the gear hinge is shown. Inparticular the teeth of the gear members are shown. Wing 3310 has uppertooth 3315U and lower tooth 3315L, and wing 3320 has lower tooth 3325Land upper tooth 3325U. Upper tooth 3315U interfaces with lower tooth3325L and upper tooth 3325U interfaces with lower tooth 3315L. Thisupper/lower tooth configuration can promote coupling of wings 3310 and3320 when used in a key mechanism.

Various embodiments have been described in detail with particularreference to certain features thereof, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the disclosure. And even though specific embodiments have beendescribed herein, it should be noted that the application is not limitedto these embodiments. In particular, any features described with respectto one embodiment may also be used in other embodiments, wherecompatible. Likewise, the features of the different embodiments may beexchanged, where compatible.

What is claimed is:
 1. A key mechanism, comprising: a keycap assembly; asupport structure; and a butterfly hinge comprising: a first wing; asecond wing adjacent the first wing; and a living hinge that pivotallycouples the first wing to the second wing such that a cavity is formedbetween first wing and the second wing, each of the first wing and thesecond wing comprising: a pair of pivot pins pivotally coupled to thesupport structure; and a pair of keycap assembly pins pivotally coupledto the keycap assembly.
 2. The key mechanism of claim 1, furthercomprising a switch secured within the cavity between the keycapassembly and the support structure, the switch operative to bias thekeycap assembly in a first position.
 3. The key mechanism of claim 2,wherein the switch comprises a dome switch operatively connected to aflexible circuit board.
 4. The key mechanism of claim 1, wherein thekeycap assembly comprises: a keycap; and a substructure coupled to aback surface of the keycap.
 5. The key mechanism of claim 4, wherein thesubstructure comprises a light guide panel.
 6. The key mechanism ofclaim 1, wherein the keycap assembly comprises a plurality of pinretaining members, each pin retaining member operative to be coupled toa respective one of the keycap assembly pins.
 7. The key mechanism ofclaim 1, wherein the support structure comprises a plurality of pivotpin retaining members, each pivot pin retaining member operative to besecurely coupled to a respective one of the pivot pins.
 8. The keymechanism of claim 1, further comprising a web that is coupled to thesupport structure, the web dimensioned so that the keycap assembly andthe butterfly hinge fit within an interior region of the web.
 9. A keymechanism, comprising: a keycap assembly; a support structure; and abutterfly hinge comprising two independently articulating wings coupledtogether by a living hinge, each wing coupled to the keycap assembly andthe support structure, wherein: each wing is operative to pivot aboutits own pivot axis during a keystroke of the key mechanism.
 10. The keymechanism of claim 9, wherein the pivot axes of both wings remain fixedin the same plane during both depressed and non-depressed positions. 11.The key mechanism of claim 9, wherein: the wings form a v-link withrespect to each other when in a non-depressed position; and both of thewings are substantially co-planar with each other when in a depressedposition.
 12. The key mechanism of claim 9, further comprising a biasingmember operative to maintain the key mechanism in its non-depressedstate when the key mechanism is not undergoing a keystroke event.
 13. Akey mechanism operative to move between a depressed position andnon-depressed position, comprising: a keycap assembly; a butterfly hingecomprising two separate wings positioned adjacent to each other andforming a cavity, each wing comprising: a pair of pivot pins; and a pairof keycap assembly pins coupled to the keycap assembly; and a a carrierplate adapted to fit within the cavity, the carrier plate havingretaining members for securing the pair of pivot pins of each wing. 14.The key mechanism of claim 13, wherein the carrier plate furthercomprises a plurality of upstop protrusions; and wherein the butterflyhinge comprises a plurality of upstops, wherein the upstop protrusionsengage the upstops to prevent the butterfly hinge from traveling beyondpredetermined position when the key mechanism is in the non-depressedposition.
 15. The key mechanism of claim 13, further comprising anelectronics package secured to the carrier plate, wherein theelectronics package includes a dome switch.
 16. The key mechanism ofclaim 15, wherein the electronics package further comprises: a lightsource; and a flexible printed circuit board.
 17. The key mechanism ofclaim 13, further comprising a circuit board fixed to the carrier plate.18. The key mechanism of claim 17, wherein the carrier plate comprises aplurality of posts extending from a bottom surface of the carrier plate,and wherein the circuit board comprises a plurality of cavitiesdimensioned to receive the posts.
 19. The key mechanism of claim 17,wherein the circuit board comprises a plurality of cutouts, the cutoutsdimensioned to receive pin receiving members of the keycap assembly whenthe key mechanism is in the depressed position.
 20. The key mechanism ofclaim 13, further comprising: a support structure having a plurality ofclips, wherein the carrier plate is secured to the support structurewith the clips; and a plurality of cutouts, the cutouts dimensioned toreceive pin receiving members of the keycap assembly when the keymechanism is in the depressed position.
 21. The key mechanism of claim13, wherein the butterfly hinge further comprises: two independentwings; and two coupling hinges to couple the wings together.
 22. The keymechanism of claim 21, wherein the coupling hinges are living hinges orgear hinges.
 23. A butterfly assembly, comprising: first and secondwings, each wing comprising: a pair of pivot pins; and a pair of keycapassembly pins; first and second hinges comprising a compliant materialovermolded onto ends of the first and second wings, thereby flexiblycoupling the first and second wings together; and a cavity formedbetween the first and second wings.
 24. The butterfly assembly of claim23, wherein the first and second hinges comprise a substantially thinportion amenable to flexing.